The background description provided herein is for the purpose of generally presenting the context of the disclosure. Work of the presently named inventors, to the extent the work is described in this background section, as well as aspects of the description that may not otherwise qualify as prior art at the time of filing, are neither expressly nor impliedly admitted as prior art against the present disclosure.
A laser is a device that emits light through a process of optical amplification based on the stimulated emission of electromagnetic radiation. The spatial coherence of a laser beam allows collimation over long distances. Applications of lasers include, among other things, laser pointers and laser projectors. Laser projectors are projectors that modulate laser beams in order to project an image at a target area. Generally, the laser projectors use a reflective screen at the target area to show the image thereon. Nevertheless, when the target area has a surface with low optical absorbance, the laser projector may project the image directly on the surface without using the screen or any other displaying device. Therefore, the laser projectors may be used to project images on surfaces such as building walls or pavement grounds for advertising purposes. There is a need to attract the pedestrians passing by the laser projecting contents of the advertisements.
Therefore, heretofore unaddressed needs still exist in the art to address the aforementioned deficiencies and inadequacies.